Air gun



N0v.2, 1937. F. M. TMUNSQN AIR GUN 2 Sheets-Sheet 1 Filed Aug. 23, 1933 2 Sheets-Sheet` 2 F. M. TOMLINSON AIR GUN Filed Aug. 23, 1933 INVENTOR. Tomi/'175017,

ATTORNEYS Nov. 2, 1937.

.wh h k@ am Patented Nov. 2, 1937 UNITED ST T GFFIQE AIR GUN Application August 23,

8 Claims.

The object of my invention is to produce a highpowered air rifle which, in spite of its high power, may be readily operative by boys of ten or more with average strength. Y

The accompanying drawings illustrate my invention:

Fig. 1 is a side elevation on a small scale.

Fig. 2 is an axial section of the gun, an intermediate portion of the barrel and the butt being omitted;

Fig. 3 is a fragmentary section showing the breech blockv mechanism in re-loading position;

Fig. 4 is a section on a, larger scale on line 4--4 of Fig. 2;

Fig. 5 is a section on a larger scale on line 5 5 of Fig. 2;

Fig. 6 is a section on the scale of Fig. 5 on the line 6-6 of Fig. 2;

Fig. '7 is a section on the scale of Fig. 5 on the line 'l-'l of Fig. 2;

Fig. 8 is a section on the scale of Fig. 5 on line 8 3 of Fig. 2;

Fig. 9 is a section on line 5 9 of Fig. 5;

Fig. 10 is a fragmentary section showing the y breech plug spring, and

Fig. 11 is a fragmentary elevation, in partial section, of the breech plug.

In the drawings indicates the breech block having in its forward end a longitudinal pocket 2i into which is sweated the rear end of the barrel 23.

The breech block 2E! is also longitudinally pocketed in its front end at 24 and into this pocket is sweated the rear end of the air compression tube 25.

Arib 26, formed conveniently of sheet metal, is brazed to the upper part of tube 25 and, extending substantially the entire length thereof forms a support for barrel 23 throughout the major portion of its length.

Block 20 is cross-bored at about its middle at 36 and rotatively fitted therein is a sleeve 3l within which is mounted breech block swivel plug 32.

Sleeve 3l and plug 32 are non-rotatively associated, as by sweating and plug 32 at one end protrudes from the side of the breech block in a reduced-radius portion 32 upon which is non-rotatively secured a ring 33 having at one point a radial linger 34 which, beyond the radius of sleeve 3 I, is axially inwardly offset to play with- 1933, Serial No. 686,427

municating with a passage 31 formed in the bottom of pocket 24 through the breech block and sleeve 3 l, and having at its upper end a tangential extension 36" communicating with a passage 38 formed in the bottom of pocket 2l and extending through the breech block and sleeve 3l, the arrangement being such that, when the breech block plug is in the position shown in Fig. 2 a continuous air passage is formed from the bottom of pocket 24 through passages 3l, 35', 36, 36", and 38 into the bottom of pocket 2 I.

The end of plug 32 opposite the reduced projection 32' lies within'bore 30 and has attached thereto one end of a torque spring 3S, the opposite end of which is inserted in a radial perforation 4E) leading from the top of the breech plug into bore 30. This end of bore 3U is closed by a washer 4I which serves as a cover for the torque spring and this cover is attached to plug 32 by a screw 42 which enters the threaded bore of plug 32 and is locked in position by a lock screw 43 which enters the opposite end of said threaded bore.

Formed in the rear end of the breech block is the bullet magazine 45 which is slightly inclined upwardly and forwardly and at its forward end communicates with bore 30 through a restricted passage 45 which is slightly larger than the bullets 46. Frictionally inserted into the rear end of magazine 45 is a sheet metal cup 4l, the bottom of which is centrally perforated at 48 and inwardly depressed, as shown at 49, the perforation 48 being slightly larger than a bullet diameter and the center end of this perforation being guarded by a light laterally displaceable spring finger 55 which permits insertion of the bullets but prevents their rearward discharge.

Brazed to the underside of the breech block at its rear end is a downwardly and rearwardly eX- tending nger 5l to which the butt 52, which is conveniently formed of sheet metal, is secured by screws 53.

Formed integrally with the butt 52 and extending forwardly from the trigger enclosing portion thereof is a U-shaped fore-arm 55 which extends along the underside of tube 25 and is secured to the depending arms of a pair of inverted U-shaped brackets 56 (Fig. 6), brazed to the underside of the tube 25, by means of screws 5l. Secured to the inner face of one wall of the trigger enclosing portion 52' of butt 52 is a U-shaped guide 6! (Fig. 5) in which is slidably mounted the rear end of a safety bar 6l adapted to engage the upwardly projecting arm 62 of a safety catch 63 pivoted at 64 within butt 52 and notched at 65 to engage an intermediate portion 66 of trigger '6l which is 4.oci

pivoted at 68 and provided with an intermediate downwardly presented shoulder 69. A light spring 6l connected at its opposite ends respectively to latch 63 and trigger Si normally urges shoulder 65 down behind the intermediate portion SB of trigger Pivoted between the side walls of the fore-arm on screw f (Figs. l and 6) is a plunger dog ll, the rear end of which projects into position to be engaged by shoulder 69 of the trigger and the forward end of which is provided with a tip 'l2 which may be projected into the interior of tube 25 through the rear end of a slot i3 formed through the underside of said tube. 'Ihe tip 'l2 of dog ll is yieldingly urged upwardly to the position shown in Fig. 1 by a spring 72' (Fig. 2).

Slidably mounted upon the middle portion of tube 25 is a sleeve 'M which is slotted along its upper side so that its ends will engage the oppositely flared edges of rib 26. This sleeve covers slot 'I3 from its forward end rearwardly almost to tip l2 of dog 'il at which point and from thence to the rear end of the sleeve it is cut away along its underside, as indicated at 'l5 (Figs. 2 and 6) to clear the upper edges of the side walls of the fore-arm.

Brazed to the rear end of sleeve 16 is the tubular hand-grip Sli, the rear end of which normally encompasses the forward end of the fore-arm, being yieldingly retained there by spring 8l which takes into notch 32 formed in the forward end of the bottom wall of the fore-arm.

Safety bar 5l projects through the front wall of the fore-arm at 83 and, at its forward end, is engaged by a light spring 84 secured to the inner face of the forward end wall of the hand grip 8l).

Pivoted at 85 (Figs. 2, 3, and 7) in the rear end of the hand grip is a U-shaped cooking latch 8f3 provided at the middle of the upper edge of its base arm with Van upwardly extending finger 87 which is normally urged upwardly by a spring 88 mounted in the hand grip. Finger 87 is normally arrested in its upward movement by engagement with the plunger 90 which accurately slidingly fits the bore of tube 25, the rear end' of this plunger being engageable by the tip i2 of dog li. The forward end of plunger 90 is Vreduced as indicated at 8| and provided with a collar S2 which presents a rearwardly presented shoulder for coaction with finger 8l and a forwardly presented shoulder as a seat for the rear end of spring 9S mounted in the forward end of tubeV 25 and held in place by cap Sil which is conveniently attached to the forward end of tube 25 by a bayonet joint and is perforated with an oil hole S5.

A rear sight 96 is formed upon or brazed to the` 9? is brazed upon the forward end of the barrel 23."

The butt 52, as previously stated, is conveniently formed of sheet metal and is preferably given sufficient depth to raise the barrel well above the butt so that the head of the operator may be held quite upright.

A shoulder plate I is conveniently in the form of a sheet metal cap hinged at le! to the lower corner of the butt and frictionally held in place by the snap edge 02 at the upper side so that the interior of the butt 52 will form a convenient receptacle for many small articles such as Boy Scouts habitually carry.

The bore of barrel 23 is, of course, accurately reamed to a diameter slightly less than the bullet diameter and the rear orifice is slightly flared t0- the bullet diameter so that as the bullet enters the barrel it is slightly swaged so as to accurately t the bore and be thus prevented from rotation during its traverse of the bore. This arrangement insures an air tight contact of the bullet with the bore and, because of the length of the barrel and non-rotation of the bullet a high degree of accuracy in the trajectory may be attained.

Plunger Si! is, of course, accurately machined to a nice sliding fit in tube 25, the middle portion of the plunger being slightly relieved to reduce friction without materially reducing the air tight fit of the plunger inthe tube at the velocity with which it may be propelled rearwardly by spring 93.

'I'he operation is as follows: The parts are shown in Figs. 1 and 2 in firing position, plunger Sil being retained, against the action of spring 93 by the tip 'i2 of dog l'l. Retraction of trigger 61 releases dog 'H and the rear cammed end of plunger 9i) depresses finger 'l2 as the plunger 90 is propelled rearwardly by spring 93. The rearward movement of plunger 90 suddenly builds up an air pressure in the rear end of tube 25 and in passages 3l, 36', 36, 36 behind the bullet 4B which lies in the rear end of passage 38 and, by the time the air pressure is built up to a point where it is suficient to drive the bullet forwardly through passage 38 (which frictionally restrains the bullet) the plunger $0 is moving at such speed that, at the moment the bullet enters the swaging orifice 23 of the barrel 23, the plunger is able, because of its velocity, to exert a hammer blow upon the confined air column so as to project the bullet through the barrel.

As the plunger 9D moves rearwardly it slides over the upper ends of tip 'I2 and linger 81 and when it comes to rest at its rear end (cushioned on the confined air column), nger 87 moves in back of collar 92 and in front of the cammed surface E93, thereby preventing rebound of the plunger.

The operator now depresses the muzzle and, grasping butt 52 in one hand and grip 80 in the other moves said grip, and plunger 9&3, forwardly to propel plunger 9B against the action of spring 39, to firing position. The initial forward movement of grip 8i) retracts spring 84 from the forward end of safety bar 6| thus permitting spring 39 to turn the breech plug in a counter-clockwise direction, the tail 34 acting upon the bar 6| to move it forwardly away from arm 52 of safety latch 53. At this moment portion 66 of trigger 67 lies beneath the forwardly projecting main arm of latch 63 and the rear end of dog 'Il lies in front of the trigger.

The counter-clockwise movement of the breech plug moves the forward end of passage 35 upwardly so that sleeve 3l will block the rear end of passage 37 and the forward end of passage 36 swings back into registry with the forward end of passage d5 (as shown in Fig. 3), whereupon a new bullet may drop from the magazine into the forward end of said passage 3S, the passage 36 being slightly less than the bullet diameter so that the bullet will be retained in this position.

When the plunger 90 has been thus projected forwardly to its forward extreme the rear end of said plunger moves in front of nger 12 thus swinging the rear end of dog 'il downwardly from in front of trigger 3l and latch 63 drops in behind trigger 6l so that the trigger may not be released until the grip 85 is fully returned to its rearmost position where, spring Bil engaging the forward end of the safety bar Ei, it propels said bar rearwardly into engagement with tail 34 to move the breech plug to firing position and to retract the safety latchJ 63 whereupon the parts are again in ring position.

It will be noted that the bullet barrel 23 and plunger barrel 'i4 are not coaxial, as has heretofore been common, and that consequently the barrel travel of the bullet is much longer than has been found possible heretofore. It is, of course, well known, that accuracy of marksmanship is seriously impeded if the gun has an overall length which is too great, because of the dii'liculty of steadily holding the gun in sighting position. It is for this reason that previous air (and plunger-type) guns, wherein the air or plunger barrel and bullet barrel are coaxial` (in tandem), afford relatively short barrel travel for the bullet, with resulting inaccuracy.

It will also be noted that in prior air guns, or plunger-type guns, the plunger, in its active stroke, moves away from the shoulder of the operator and that the impact of such a plunger tends to move the gun away from its shoulder seat. Such action inevitably results in unsteadiness of the arm at the very instant when steadiness is most vital, and very materially diminishes the possible accuracy of trajectory. In my arm, it will be noted that the pressure-producing plunger SM, in its active stroke, moves rearwardly so that its impact seats the arm more firmly upon the shoulder of the operator at the very instant when such firmness is most to be desired.

As a consequence, even ignoring for the moment the longer barrel travel of the bullet in my arm, much greater accuracy can be attained. The combination, found in my arm, of a full length bullet barrel and a rearwardly impacting plunger and a relatively long air chamber, makes possible the attainment of very much greater accuracy than has heretofore been possible with air guns.

I claim as my invention:

1. In an air gun, a breech-block having a transverse bore, a bullet-barrel carried by said block, an air-barrel carried by said block, abulletmagazine, a plug rotatably mounted in said transverse bore of the breech-block, and provided with a U-shaped passage registrable at its ends with the bullet barrel and the air barrel and at its air discharge end with the magazine outlet, and provided with a portion closing the magazine outlet when said passage connects the two barrels, said passage having at its air-discharge end, a bullet seat, a plunger reciprocable in the air-barrel, a spring acting upon said plunger to drive it toward the breech-block, a hand grip slidable toward and from the breech-block, means carried by the hand-grip for engaging said plunger to move it in opposition to said spring, a latch capable of restraining said plunger in opposition to said spring, trigger mechanism for releasing said latch, and a spring normally urging said plug to bullet-receiving position.

2. In an air gun, a breech-block having a transverse bore, a bullet-barrel carried by said block, an air-barrel carried by said block, a bullet-magazine, a plug rotatably mounted in said transverse bore of the breech-block and provided with a U-shaped passage registrable at its ends with the bullet barrel and the air barrel and at its air discharge end with the magazine outlet, and provided with a portion closing the magazine outlet when said passage connects the two barrels, said passage having, at its air-discharge end, a bullet seat, a plunger reciprocable in the air-barrel, a spring acting upon said plunger to drive it toward the breech-block, a hand grip slidable toward and from the breechblock, means carried by the hand-grip for engaging said plunger to move it in opposition to said spring, a latch capable of restraining said plungerv in opposition to said spring, trigger mechanism for releasing said latch, a latch arranged to normally restrain the trigger, means carried by the hand grip for moving the plug to register its U-shaped passage with the two barrels, and to withdraw said last-mentioned latch, and a spring normally urging said plug to bulletreceiving position.

3. In an air gun, a bullet-barrel, a separate air-barrel substantially parallel with and alongside the bullet-barrel, a vplunger slidably mounted in the air barrel, a spring arranged in the muzzle end of the air-barrel to drive said plunger toward the breech of the gun, an air conduit between the breech-ends of said two barrels, a detent to restrain said plunger against the action of said spring, a hand grip slidable lengthwise of said barrels, and means carried by said grip engageable with said plunger between the breech and the breech end of the spring by which said plunger may be moved forwardly in its barrel against said spring.

4. In an air gun, a breech block carrying substantially parallel adjacent air and bullet barrels each communicating at its rear end with a transverse bore having an axis substantially at right angles to the barrel bores, a plug oscillable in said transverse bore comprising a central portion having a U-srhaped circumferential groove and an external sleeve portion having two perforations registering with the opposite ends of said groove, a bullet magazine having a discharge passage communicating with said transverse bore and registrable with the sleeve perforation at the delivery end of said groove when the plug is reversely oscillated, said groove being restricted to prevent bullet-passage therethrough.

5. In an air gun, a bullet-barrel, an air-barrel substantially parallel with and alongside the bullet barrel, a breech-block supporting said barrels and having a passage connecting the adjacent rear ends of said barrels, a plunger having a bore fitting length approximating plunger travel reciprocable within the air barrel, an obstructor arranged to engage the rear end of said plunger to restrain rearward movement of the plunger, trigger mechanism controlling said obstructor, a compression spring arranged in the forward end of the air barrel and engaging the forward end of the plunger, a hand-grip slidable axially of the barrels, means carried by said hand-grip for engaging the plunger between the breech and breech end of the spring to propel the plunger forwardly in opposition to the spring, a safety latch normally obstructing release of the obstructor, and retracting means for said safety latch comprising an element engaged by the hand-grip in its rear-most position to retract the safety-latch.

6. In an air gun, an air barrel, a plunger slidingly mounted in said barrel and having an axially extensive fit therein, a compression spring mounted in the forward end of the barrel and engaging the forward end of the plunger, trigger mechanism embodying an obstructor engageable with the rear end of the plunger in opposition to the spring, a segmental sleeve slidably mounted on the barrel, a hand-grip carried by said sleeve by which the sleeve may be axially reciprocated on the barrel, one-way means carried by said sleeve to engage the plunger in oppo-sition to the spring, a safety-latch normally ob- Y compression spring v:mounted in the forward end of the barrel and engaging the forward end of the plunger, trigger mechanism embodying an obstructor engageable with the rear end of the plunger in opposition to the spring, a segmental sleeve slidably mounted Yonthe barrel, a handgrip carried by said sleeve by which the sleeve may be axially reciprocated on the barrel, and

one-way means Carried by said sleeve to engage the plunger between the breech and the breech end of the spring in opposition to the spring.

8. In an air gun, an air barrel, a plunger slidably mounted in said barrel, a. compression spring arranged in the muzzle end of said barrel and acting on said plunger, a hand-grip comprising a segmental sleeve embracing said barrel and longitudinally slidable thereon, and a latch carried by said hand-grip and engageable with the plunger between the breech and the breech end of the spring to drive the plunger forwardly in the barrel against the action of the spring by forward movement of the hand-grip on the barrel.

FAY M. TOMLINSON. 

